- 27 Sep, 2021 8 commits
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Magnus Karlsson authored
Fix a problem where the fill ring was populated with too many entries. If number of buffers in the umem was smaller than the fill ring size, the code used to loop over from the beginning of the umem and start putting the same buffers in again. This is racy indeed as a later packet can be received overwriting an earlier one before the Rx thread manages to validate it. Signed-off-by:
Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-9-magnus.karlsson@gmail.com
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Magnus Karlsson authored
Fix missing initialization of the member rx_pkt_nb in the packet stream. This leads to some tests declaring success too early as the test thought all packets had already been received. Signed-off-by:
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Magnus Karlsson authored
Optimize for the aligned case by precomputing the parameter values of the xdp_buff_xsk and xdp_buff structures in the heads array. We can do this as the heads array size is equal to the number of chunks in the umem for the aligned case. Then every entry in this array will reflect a certain chunk/frame and can therefore be prepopulated with the correct values and we can drop the use of the free_heads stack. Note that it is not possible to allocate more buffers than what has been allocated in the aligned case since each chunk can only contain a single buffer. We can unfortunately not do this in the unaligned case as one chunk might contain multiple buffers. In this case, we keep the old scheme of populating a heads entry every time it is used and using the free_heads stack. Also move xp_release() and xp_get_handle() to xsk_buff_pool.h. They were for some reason in xsk.c even though they are buffer pool operations. Signed-off-by:
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Magnus Karlsson authored
Use the new xsk batched rx allocation interface for the zero-copy data path. As the array of struct xdp_buff pointers kept by the driver is really a ring that wraps, the allocation routine is modified to detect a wrap and in that case call the allocation function twice. The allocation function cannot deal with wrapped rings, only arrays. As we now know exactly how many buffers we get and that there is no wrapping, the allocation function can be simplified even more as all if-statements in the allocation loop can be removed, improving performance. Signed-off-by:
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Magnus Karlsson authored
Use the new xsk batched rx allocation interface for the zero-copy data path. As the array of struct xdp_buff pointers kept by the driver is really a ring that wraps, the allocation routine is modified to detect a wrap and in that case call the allocation function twice. The allocation function cannot deal with wrapped rings, only arrays. As we now know exactly how many buffers we get and that there is no wrapping, the allocation function can be simplified even more as all if-statements in the allocation loop can be removed, improving performance. Signed-off-by:
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Magnus Karlsson authored
In order to use the new xsk batched buffer allocation interface, a pointer to an array of struct xsk_buff pointers need to be provided so that the function can put the result of the allocation there. In the ice driver, we already have a ring that stores pointers to xdp_buffs. This is only used for the xsk zero-copy driver and is a union with the structure that is used for the regular non zero-copy path. Unfortunately, that structure is larger than the xdp_buffs pointers which mean that there will be a stride (of 20 bytes) between each xdp_buff pointer. And feeding this into the xsk_buff_alloc_batch interface will not work since it assumes a regular array of xdp_buff pointers (each 8 bytes with 0 bytes in-between them on a 64-bit system). To fix this, remove the xdp_buff pointer from the rx_buf union and move it one step higher to the union above which only has pointers to arrays in it. This solves the problem and we can directly feed the SW ring of xdp_buff pointers straight into the allocation function in the next patch when that interface is used. This will improve performance. Signed-off-by:
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Magnus Karlsson authored
Add a new driver interface xsk_buff_alloc_batch() offering batched buffer allocations to improve performance. The new interface takes three arguments: the buffer pool to allocated from, a pointer to an array of struct xdp_buff pointers which will contain pointers to the allocated xdp_buffs, and an unsigned integer specifying the max number of buffers to allocate. The return value is the actual number of buffers that the allocator managed to allocate and it will be in the range 0 <= N <= max, where max is the third parameter to the function. u32 xsk_buff_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max); A second driver interface is also introduced that need to be used in conjunction with xsk_buff_alloc_batch(). It is a helper that sets the size of struct xdp_buff and is used by the NIC Rx irq routine when receiving a packet. This helper sets the three struct members data, data_meta, and data_end. The two first ones is in the xsk_buff_alloc() case set in the allocation routine and data_end is set when a packet is received in the receive irq function. This unfortunately leads to worse performance since the xdp_buff is touched twice with a long time period in between leading to an extra cache miss. Instead, we fill out the xdp_buff with all 3 fields at one single point in time in the driver, when the size of the packet is known. Hence this helper. Note that the driver has to use this helper (or set all three fields itself) when using xsk_buff_alloc_batch(). xsk_buff_alloc() works as before and does not require this. void xsk_buff_set_size(struct xdp_buff *xdp, u32 size); Signed-off-by: -
Magnus Karlsson authored
Get rid of the unused entry "unaligned" in struct xdp_buff_xsk. Signed-off-by:
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- 26 Sep, 2021 5 commits
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Alexei Starovoitov authored
Martin KaFai says: ==================== The verifier currently does not save the reg state when spilling <8byte bounded scalar to the stack. The bpf program will be incorrectly rejected when this scalar is refilled to the reg and then used to offset into a packet header. The later patch has a simplified bpf prog from a real use case to demonstrate this case. The current work around is to reparse the packet again such that this offset scalar is close to where the packet data will be accessed to avoid the spill. Thus, the header is parsed twice. The llvm patch [1] will align the <8bytes spill to the 8-byte stack address. This set is to make the necessary changes in verifier to support <8byte scalar spill and refill. [1] https://reviews.llvm.org/D109073 v2: - Changed the xdpwall selftest in patch 3 to trigger a u32 spill at a non 8-byte aligned stack address. The v1 has simplified the real example too much such that it only triggers a u32 spill but does not spill at a non 8-byte aligned stack address. - Changed README.rst in patch 3 to explain the llvm dependency for the xdpwall test. ==================== Signed-off-by:
Alexei Starovoitov <ast@kernel.org>
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Martin KaFai Lau authored
This patch adds a few verifier tests for <8-byte spill and refill. Signed-off-by:
Martin KaFai Lau <kafai@fb.com> Signed-off-by:
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Martin KaFai Lau authored
It is a simplified example that can trigger a 32bit scalar spill. The const scalar is refilled and added to a skb->data later. Since the reg state of the 32bit scalar spill is not saved now, adding the refilled reg to skb->data and then comparing it with skb->data_end cannot verify the skb->data access. With the earlier verifier patch and the llvm patch [1]. The verifier can correctly verify the bpf prog. Here is the snippet of the verifier log that leads to verifier conclusion that the packet data is unsafe to read. The log is from the kerne without the previous verifier patch to save the <8-byte scalar spill. 67: R0=inv1 R1=inv17 R2=invP2 R3=inv1 R4=pkt(id=0,off=68,r=102,imm=0) R5=inv102 R6=pkt(id=0,off=62,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 67: (63) *(u32 *)(r10 -12) = r5 68: R0=inv1 R1=inv17 R2=invP2 R3=inv1 R4=pkt(id=0,off=68,r=102,imm=0) R5=inv102 R6=pkt(id=0,off=62,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmm???? ... 101: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 101: (61) r1 = *(u32 *)(r10 -12) 102: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 102: (bc) w1 = w1 103: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=0,off=0,r=102,imm=0) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm 103: (0f) r7 += r1 last_idx 103 first_idx 67 regs=2 stack=0 before 102: (bc) w1 = w1 regs=2 stack=0 before 101: (61) r1 = *(u32 *)(r10 -12) 104: R0_w=map_value_or_null(id=2,off=0,ks=16,vs=1,imm=0) R1_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6_w=pkt(id=0,off=70,r=102,imm=0) R7_w=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=inv17 R10=fp0 fp-16=mmmmmmmm ... 127: R0_w=inv1 R1=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 127: (bf) r1 = r7 128: R0_w=inv1 R1_w=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 128: (07) r1 += 8 129: R0_w=inv1 R1_w=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9_w=invP17 R10=fp0 fp-16=mmmmmmmm 129: (b4) w0 = 1 130: R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 130: (2d) if r1 > r8 goto pc-66 R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 131: R0=inv1 R1=pkt(id=3,off=8,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R6=pkt(id=0,off=70,r=102,imm=0) R7=pkt(id=3,off=0,r=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R8=pkt_end(id=0,off=0,imm=0) R9=invP17 R10=fp0 fp-16=mmmmmmmm 131: (69) r6 = *(u16 *)(r7 +0) invalid access to packet, off=0 size=2, R7(id=3,off=0,r=0) R7 offset is outside of the packet [1]: https://reviews.llvm.org/D109073Signed-off-by:
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Martin KaFai Lau authored
The verifier currently does not save the reg state when spilling <8byte bounded scalar to the stack. The bpf program will be incorrectly rejected when this scalar is refilled to the reg and then used to offset into a packet header. The later patch has a simplified bpf prog from a real use case to demonstrate this case. The current work around is to reparse the packet again such that this offset scalar is close to where the packet data will be accessed to avoid the spill. Thus, the header is parsed twice. The llvm patch [1] will align the <8bytes spill to the 8-byte stack address. This can simplify the verifier support by avoiding to store multiple reg states for each 8 byte stack slot. This patch changes the verifier to save the reg state when spilling <8bytes scalar to the stack. This reg state saving is limited to spill aligned to the 8-byte stack address. The current refill logic has already called coerce_reg_to_size(), so coerce_reg_to_size() is not called on state->stack[spi].spilled_ptr during spill. When refilling in check_stack_read_fixed_off(), it checks the refill size is the same as the number of bytes marked with STACK_SPILL before restoring the reg state. When restoring the reg state to state->regs[dst_regno], it needs to avoid the state->regs[dst_regno].subreg_def being over written because it has been marked by the check_reg_arg() earlier [check_mem_access() is called after check_reg_arg() in do_check()]. Reordering check_mem_access() and check_reg_arg() will need a lot of changes in test_verifier's tests because of the difference in verifier's error message. Thus, the patch here is to save the state->regs[dst_regno].subreg_def first in check_stack_read_fixed_off(). There are cases that the verifier needs to scrub the spilled slot from STACK_SPILL to STACK_MISC. After this patch the spill is not always in 8 bytes now, so it can no longer assume the other 7 bytes are always marked as STACK_SPILL. In particular, the scrub needs to avoid marking an uninitialized byte from STACK_INVALID to STACK_MISC. Otherwise, the verifier will incorrectly accept bpf program reading uninitialized bytes from the stack. A new helper scrub_spilled_slot() is created for this purpose. [1]: https://reviews.llvm.org/D109073Signed-off-by:
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Martin KaFai Lau authored
Every 8 bytes of the stack is tracked by a bpf_stack_state. Within each bpf_stack_state, there is a 'u8 slot_type[8]' to track the type of each byte. Verifier tests slot_type[0] == STACK_SPILL to decide if the spilled reg state is saved. Verifier currently only saves the reg state if the whole 8 bytes are spilled to the stack, so checking the slot_type[7] is the same as checking slot_type[0]. The later patch will allow verifier to save the bounded scalar reg also for <8 bytes spill. There is a llvm patch [1] to ensure the <8 bytes spill will be 8-byte aligned, so checking slot_type[7] instead of slot_type[0] is required. While at it, this patch refactors the slot_type[0] == STACK_SPILL test into a new function is_spilled_reg() and change the slot_type[0] check to slot_type[7] check in there also. [1] https://reviews.llvm.org/D109073Signed-off-by:
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- 24 Sep, 2021 1 commit
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Yonghong Song authored
With clang build kernel (adding LLVM=1 to kernel and selftests/bpf build command line), I hit the following test failure: $ ./test_progs -t btf_dump ... btf_dump_data:PASS:ensure expected/actual match 0 nsec btf_dump_data:FAIL:find type id unexpected find type id: actual -2 < expected 0 btf_dump_data:FAIL:find type id unexpected find type id: actual -2 < expected 0 test_btf_dump_int_data:FAIL:dump __int128 unexpected error: -2 (errno 2) #15/9 btf_dump/btf_dump: int_data:FAIL Further analysis showed gcc build kernel has type "__int128" in dwarf/BTF and it doesn't exist in clang build kernel. Code searching for kernel code found the following: arch/s390/include/asm/types.h: unsigned __int128 pair; crypto/ecc.c: unsigned __int128 m = (unsigned __int128)left * right; include/linux/math64.h: return (u64)(((unsigned __int128)a * mul) >> shift); include/linux/math64.h: return (u64)(((unsigned __int128)a * mul) >> shift); lib/ubsan.h:typedef __int128 s_max; lib/ubsan.h:typedef unsigned __int128 u_max; In my case, CONFIG_UBSAN is not enabled. Even if we only have "unsigned __int128" in the code, somehow gcc still put "__int128" in dwarf while clang didn't. Hence current test works fine for gcc but not for clang. Enabling CONFIG_UBSAN is an option to provide __int128 type into dwarf reliably for both gcc and clang, but not everybody enables CONFIG_UBSAN in their kernel build. So the best choice is to use "unsigned __int128" type which is available in both clang and gcc build kernels. But clang and gcc dwarf encoded names for "unsigned __int128" are different: [$ ~] cat t.c unsigned __int128 a; [$ ~] gcc -g -c t.c && llvm-dwarfdump t.o | grep __int128 DW_AT_type (0x00000031 "__int128 unsigned") DW_AT_name ("__int128 unsigned") [$ ~] clang -g -c t.c && llvm-dwarfdump t.o | grep __int128 DW_AT_type (0x00000033 "unsigned __int128") DW_AT_name ("unsigned __int128") The test change in this patch tries to test type name before doing actual test. Signed-off-by:Yonghong Song <yhs@fb.com> Signed-off-by:
Andrii Nakryiko <andrii@kernel.org> Reviewed-by:
Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20210924025856.2192476-1-yhs@fb.com
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- 22 Sep, 2021 7 commits
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Alexei Starovoitov authored
Document and clarify BPF licensing. Signed-off-by:
Simon Horman <simon.horman@corigine.com> Acked-by:
Toke Høiland-Jørgensen <toke@redhat.com> Acked-by:
Joe Stringer <joe@cilium.io> Acked-by:
Lorenz Bauer <lmb@cloudflare.com> Acked-by:
Dave Thaler <dthaler@microsoft.com> Acked-by:
Stephen Hemminger <stephen@networkplumber.org> Acked-by:
Jesper Dangaard Brouer <brouer@redhat.com> Acked-by:
KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210917230034.51080-1-alexei.starovoitov@gmail.com
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Jiri Benc authored
The 'arp' command is deprecated and is another dependency of the selftest. Just use 'ip neigh', the test depends on iproute2 already. Signed-off-by:
Jiri Benc <jbenc@redhat.com> Signed-off-by:
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Alexei Starovoitov authored
Andrii Nakryiko says: ==================== Implement libbpf support for attaching uprobes/uretprobes using legacy tracefs interfaces. This is a logical complement to recently landed legacy kprobe support ([0]). This patch refactors existing legacy kprobe code to be more uniform with uprobe code as well, making the logic easier to compare and follow. This patch set also fixes two bugs recently found by Coverity in legacy kprobe handling code, and thus subsumes previously submitted two patches ([1]): original patch #1 is kept as is, while original patch #2 was dropped because patch #3 of the current series refactors and fixes affected code. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20210912064844.3181742-1-rafaeldtinoco@gmail.com/ [1] https://patchwork.kernel.org/project/netdevbpf/list/?series=549977&state=* v1->v2: - drop 'legacy = true' debug left-over and explain legacy check (Alexei). ==================== Signed-off-by:
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Andrii Nakryiko authored
Similarly to recently added legacy kprobe attach interface support through tracefs, support attaching uprobes using the legacy interface if host kernel doesn't support newer FD-based interface. For uprobes event name consists of "libbpf_" prefix, PID, sanitized binary path and offset within that binary. Structuraly the code is aligned with kprobe logic refactoring in previous patch. struct bpf_link_perf is re-used and all the same legacy_probe_name and legacy_is_retprobe fields are used to ensure proper cleanup on bpf_link__destroy(). Users should be aware, though, that on old kernels which don't support FD-based interface for kprobe/uprobe attachment, if the application crashes before bpf_link__destroy() is called, uprobe legacy events will be left in tracefs. This is the same limitation as with legacy kprobe interfaces. Signed-off-by:
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Andrii Nakryiko authored
Refactor legacy kprobe handling code to follow the same logic as uprobe legacy logic added in the next patchs: - add append_to_file() helper that makes it simpler to work with tracefs file-based interface for creating and deleting probes; - move out probe/event name generation outside of the code that adds/removes it, which simplifies bookkeeping significantly; - change the probe name format to start with "libbpf_" prefix and include offset within kernel function; - switch 'unsigned long' to 'size_t' for specifying kprobe offsets, which is consistent with how uprobes define that, simplifies printf()-ing internally, and also avoids unnecessary complications on architectures where sizeof(long) != sizeof(void *). This patch also implicitly fixes the problem with invalid open() error handling present in poke_kprobe_events(), which (the function) this patch removes. Fixes: ca304b40 ("libbpf: Introduce legacy kprobe events support") Signed-off-by: -
Andrii Nakryiko authored
Make sure to not use ref_ctr_off feature when running on old kernels that don't support this feature. This allows to test libbpf's legacy kprobe and uprobe logic on old kernels. Signed-off-by:
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Andrii Nakryiko authored
In some error scenarios legacy_probe string won't be free()'d. Fix this. This was reported by Coverity static analysis. Fixes: ca304b40 ("libbpf: Introduce legacy kprobe events support") Signed-off-by:
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- 21 Sep, 2021 3 commits
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Gokul Sivakumar authored
The ARP table that is dumped when the xdp_router_ipv4 process is launched has the IP address & MAC address in non-readable network byte order format, also the alignment is off when printing the table. Address HwAddress 160000e0 1600005e0001 ff96a8c0 ffffffffffff faffffef faff7f5e0001 196a8c0 9607871293ea fb0000e0 fb00005e0001 0 0 196a8c0 9607871293ea ffff11ac ffffffffffff faffffef faff7f5e0001 fb0000e0 fb00005e0001 160000e0 1600005e0001 160000e0 1600005e0001 faffffef faff7f5e0001 fb0000e0 fb00005e0001 40011ac 40011ac4202 Fix this by converting the "Address" field from network byte order Hex into dotted decimal notation IPv4 format and "HwAddress" field from network byte order Hex into Colon separated Hex format. Also fix the aligntment of the fields in the ARP table. Address HwAddress 224.0.0.22 01:00:5e:00:00:16 192.168.150.255 ff:ff:ff:ff:ff:ff 239.255.255.250 01:00:5e:7f:ff:fa 192.168.150.1 ea:93:12:87:07:96 224.0.0.251 01:00:5e:00:00:fb 0.0.0.0 00:00:00:00:00:00 192.168.150.1 ea:93:12:87:07:96 172.17.255.255 ff:ff:ff:ff:ff:ff 239.255.255.250 01:00:5e:7f:ff:fa 224.0.0.251 01:00:5e:00:00:fb 224.0.0.22 01:00:5e:00:00:16 224.0.0.22 01:00:5e:00:00:16 239.255.255.250 01:00:5e:7f:ff:fa 224.0.0.251 01:00:5e:00:00:fb 172.17.0.4 02:42:ac:11:00:04 Signed-off-by:
Gokul Sivakumar <gokulkumar792@gmail.com> Signed-off-by:
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Gokul Sivakumar authored
The route table that is dumped when the xdp_router_ipv4 process is launched has the "Gateway" field in non-readable network byte order format, also the alignment is off when printing the table. Destination Gateway Genmask Metric Iface 0.0.0.0 196a8c0 0 0 enp7s0 0.0.0.0 196a8c0 0 0 wlp6s0 169.254.0.0 196a8c0 16 0 enp7s0 172.17.0.0 0 16 0 docker0 192.168.150.0 0 24 0 enp7s0 192.168.150.0 0 24 0 wlp6s0 Fix this by converting the "Gateway" field from network byte order Hex into dotted decimal notation IPv4 format and "Genmask" from CIDR notation into dotted decimal notation IPv4 format. Also fix the aligntment of the fields in the route table. Destination Gateway Genmask Metric Iface 0.0.0.0 192.168.150.1 0.0.0.0 0 enp7s0 0.0.0.0 192.168.150.1 0.0.0.0 0 wlp6s0 169.254.0.0 192.168.150.1 255.255.0.0 0 enp7s0 172.17.0.0 0.0.0.0 255.255.0.0 0 docker0 192.168.150.0 0.0.0.0 255.255.255.0 0 enp7s0 192.168.150.0 0.0.0.0 255.255.255.0 0 wlp6s0 Signed-off-by:
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Grant Seltzer authored
This adds comments above functions in libbpf.h which document their uses. These comments are of a format that doxygen and sphinx can pick up and render. These are rendered by libbpf.readthedocs.org These doc comments are for: - bpf_object__find_map_by_name() - bpf_map__fd() - bpf_map__is_internal() - libbpf_get_error() - libbpf_num_possible_cpus() Signed-off-by:
Grant Seltzer <grantseltzer@gmail.com> Signed-off-by:
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- 17 Sep, 2021 16 commits
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Alexei Starovoitov authored
Dave Marchevsky says: ==================== This series introduces a new helper, bpf_trace_vprintk, which functions like bpf_trace_printk but supports > 3 arguments via a pseudo-vararg u64 array. The bpf_printk libbpf convenience macro is modified to use bpf_trace_vprintk when > 3 varargs are passed, otherwise the previous behavior - using bpf_trace_printk - is retained. Helper functions and macros added during the implementation of bpf_seq_printf and bpf_snprintf do most of the heavy lifting for bpf_trace_vprintk. There's no novel format string wrangling here. Usecase here is straightforward: Giving BPF program writers a more powerful printk will ease development of BPF programs, particularly during debugging and testing, where printk tends to be used. This feature was proposed by Andrii in libbpf mirror's issue tracker [1]. [1] https://github.com/libbpf/libbpf/issues/315 v5 -> v6: Rebase to pick up newly-added helper v4 -> v5: * patch 8: added test for "%pS" format string w/ NULL fmt arg [Daniel] * patch 8: dmesg -> /sys/kernel/debug/tracing/trace_pipe in commit message [Andrii] * patch 9: squash into patch 8, remove the added test in favor of just bpf_printk'ing in patch 8's test [Andrii] * migrate comment to /* */ * header comments improved$ * uapi/linux/bpf.h: u64 -> long return type [Daniel] * uapi/linux/bpf.h: function description explains benefit of bpf_trace_vprintk over bpf_trace_printk [Daniel] * uapi/linux/bpf.h: added patch explaining that data_len should be a multiple of 8 in bpf_seq_printf, bpf_snprintf descriptions [Daniel] * tools/lib/bpf/bpf_helpers.h: move comment to new bpf_printk [Andrii] * rebase v3 -> v4: * Add patch 2, which migrates reference_tracking prog_test away from bpf_program__load. Could be placed a bit later in the series, but wanted to keep the actual vprintk-related patches contiguous * Add patch 9, which adds a program w/ 0 fmt arg bpf_printk to vprintk test * bpf_printk convenience macro isn't multiline anymore, so simplify [Andrii] * Add some comments to ___bpf_pick_printk to make it more obvious when implementation switches from printk to vprintk [Andrii] * BPF_PRINTK_FMT_TYPE -> BPF_PRINTK_FMT_MOD for 'static const' fmt string in printk wrapper macro [Andrii] * checkpatch.pl doesn't like this, says "Macros with complex values should be enclosed in parentheses". Strange that it didn't have similar complaints about v3's BPF_PRINTK_FMT_TYPE. Regardless, IMO the complaint is not highlighting a real issue in the case of this macro. * Fix alignment of __bpf_vprintk and __bpf_pick_printk [Andrii] * rebase v2 -> v3: * Clean up patch 3's commit message [Alexei] * Add patch 4, which modifies __bpf_printk to use 'static const char' to store fmt string with fallback for older kernels [Andrii] * rebase v1 -> v2: * Naming conversation seems to have gone in favor of keeping bpf_trace_vprintk, names are unchanged * Patch 3 now modifies bpf_printk convenience macro to choose between __bpf_printk and __bpf_vprintk 'implementation' macros based on arg count. __bpf_vprintk is a renaming of bpf_vprintk convenience macro from v1, __bpf_printk is the existing bpf_printk implementation. This patch could use some scrutiny as I think current implementation may regress developer experience in a specific case, turning a compile-time error into a load-time error. Unclear to me how common the case is, or whether the macro magic I chose is ideal. * char ___fmt[] to static const char ___fmt[] change was not done, wanted to leave __bpf_printk 'implementation' macro unchanged for v2 to ease discussion of above point * Removed __always_inline from __set_printk_clr_event [Andrii] * Simplified bpf_trace_printk docstring to refer to other functions instead of copy/pasting and avoid specifying 12 vararg limit [Andrii] * Migrated trace_printk selftest to use ASSERT_ instead of CHECK * Adds new patch 5, previous patch 5 is now 6 * Migrated trace_vprintk selftest to use ASSERT_ instead of CHECK, open_and_load instead of separate open, load [Andrii] * Patch 2's commit message now correctly mentions trace_pipe instead of dmesg [Andrii] ==================== Signed-off-by:
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Dave Marchevsky authored
Since the data_len in these two functions is a byte len of the preceding u64 *data array, it must always be a multiple of 8. If this isn't the case both helpers error out, so let's make the requirement explicit so users don't need to infer it. Signed-off-by:
Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by:
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Dave Marchevsky authored
This commit adds a test prog for vprintk which confirms that: * bpf_trace_vprintk is writing to /sys/kernel/debug/tracing/trace_pipe * __bpf_vprintk macro works as expected * >3 args are printed * bpf_printk w/ 0 format args compiles * bpf_trace_vprintk call w/ a fmt specifier but NULL fmt data fails Approach and code are borrowed from trace_printk test. Signed-off-by:
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Dave Marchevsky authored
Guidance for new tests is to use ASSERT macros instead of CHECK. Since trace_vprintk test will borrow heavily from trace_printk's, migrate its CHECKs so it remains obvious that the two are closely related. Signed-off-by:
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Dave Marchevsky authored
Since commit 368cb0e7 ("bpftool: Make probes which emit dmesg warnings optional"), some helpers aren't probed by bpftool unless `full` arg is added to `bpftool feature probe`. bpf_trace_vprintk can emit dmesg warnings when probed, so include it. Signed-off-by:
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Dave Marchevsky authored
The __bpf_printk convenience macro was using a 'char' fmt string holder as it predates support for globals in libbpf. Move to more efficient 'static const char', but provide a fallback to the old way via BPF_NO_GLOBAL_DATA so users on old kernels can still use the macro. Signed-off-by:
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Dave Marchevsky authored
Instead of being a thin wrapper which calls into bpf_trace_printk, libbpf's bpf_printk convenience macro now chooses between bpf_trace_printk and bpf_trace_vprintk. If the arg count (excluding format string) is >3, use bpf_trace_vprintk, otherwise use the older helper. The motivation behind this added complexity - instead of migrating entirely to bpf_trace_vprintk - is to maintain good developer experience for users compiling against new libbpf but running on older kernels. Users who are passing <=3 args to bpf_printk will see no change in their bytecode. __bpf_vprintk functions similarly to BPF_SEQ_PRINTF and BPF_SNPRINTF macros elsewhere in the file - it allows use of bpf_trace_vprintk without manual conversion of varargs to u64 array. Previous implementation of bpf_printk macro is moved to __bpf_printk for use by the new implementation. This does change behavior of bpf_printk calls with >3 args in the "new libbpf, old kernels" scenario. Before this patch, attempting to use 4 args to bpf_printk results in a compile-time error. After this patch, using bpf_printk with 4 args results in a trace_vprintk helper call being emitted and a load-time failure on older kernels. Signed-off-by:
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Dave Marchevsky authored
This helper is meant to be "bpf_trace_printk, but with proper vararg support". Follow bpf_snprintf's example and take a u64 pseudo-vararg array. Write to /sys/kernel/debug/tracing/trace_pipe using the same mechanism as bpf_trace_printk. The functionality of this helper was requested in the libbpf issue tracker [0]. [0] Closes: https://github.com/libbpf/libbpf/issues/315Signed-off-by:
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Dave Marchevsky authored
bpf_program__load is not supposed to be used directly. Replace it with bpf_object__ APIs for the reference_tracking prog_test, which is the last offender in bpf selftests. Some additional complexity is added for this test, namely the use of one bpf_object to iterate through progs, while a second bpf_object is created and opened/closed to test actual loading of progs. This is because the test was doing bpf_program__load then __unload to test loading of individual progs and same semantics with bpf_object__load/__unload result in failure to load an __unload-ed obj. Signed-off-by:
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Dave Marchevsky authored
MAX_SNPRINTF_VARARGS and MAX_SEQ_PRINTF_VARARGS are used by bpf helpers bpf_snprintf and bpf_seq_printf to limit their varargs. Both call into bpf_bprintf_prepare for print formatting logic and have convenience macros in libbpf (BPF_SNPRINTF, BPF_SEQ_PRINTF) which use the same helper macros to convert varargs to a byte array. Changing shared functionality to support more varargs for either bpf helper would affect the other as well, so let's combine the _VARARGS macros to make this more obvious. Signed-off-by:
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski authored
Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-09-17 We've added 63 non-merge commits during the last 12 day(s) which contain a total of 65 files changed, 2653 insertions(+), 751 deletions(-). The main changes are: 1) Streamline internal BPF program sections handling and bpf_program__set_attach_target() in libbpf, from Andrii. 2) Add support for new btf kind BTF_KIND_TAG, from Yonghong. 3) Introduce bpf_get_branch_snapshot() to capture LBR, from Song. 4) IMUL optimization for x86-64 JIT, from Jie. 5) xsk selftest improvements, from Magnus. 6) Introduce legacy kprobe events support in libbpf, from Rafael. 7) Access hw timestamp through BPF's __sk_buff, from Vadim. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits) selftests/bpf: Fix a few compiler warnings libbpf: Constify all high-level program attach APIs libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7 selftests/bpf: Switch fexit_bpf2bpf selftest to set_attach_target() API libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target() libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs selftests/bpf: Stop using relaxed_core_relocs which has no effect libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id() bpf: Update bpf_get_smp_processor_id() documentation libbpf: Add sphinx code documentation comments selftests/bpf: Skip btf_tag test if btf_tag attribute not supported docs/bpf: Add documentation for BTF_KIND_TAG selftests/bpf: Add a test with a bpf program with btf_tag attributes selftests/bpf: Test BTF_KIND_TAG for deduplication selftests/bpf: Add BTF_KIND_TAG unit tests selftests/bpf: Change NAME_NTH/IS_NAME_NTH for BTF_KIND_TAG format selftests/bpf: Test libbpf API function btf__add_tag() bpftool: Add support for BTF_KIND_TAG libbpf: Add support for BTF_KIND_TAG libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag ... ==================== Link: https://lore.kernel.org/r/20210917173738.3397064-1-ast@kernel.orgSigned-off-by:
Jakub Kicinski <kuba@kernel.org>
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Florian Fainelli authored
72165 is a 16nm process SoC with a 10/100 integrated Ethernet PHY, create a new macro and set of functions for this different process type. Signed-off-by:
Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20210917181551.2836036-1-f.fainelli@gmail.comSigned-off-by:
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Nathan Chancellor authored
Clang warns twice: drivers/ptp/ptp_ocp.c:2065:16: error: operator '?:' has lower precedence than '&'; '&' will be evaluated first [-Werror,-Wbitwise-conditional-parentheses] on & map ? " ON" : "OFF", src); ~~~~~~~~ ^ drivers/ptp/ptp_ocp.c:2065:16: note: place parentheses around the '&' expression to silence this warning on & map ? " ON" : "OFF", src); ^ ( ) drivers/ptp/ptp_ocp.c:2065:16: note: place parentheses around the '?:' expression to evaluate it first on & map ? " ON" : "OFF", src); ^ on and map are both booleans so this should be a logical AND, which clears up the operator precedence issue. Fixes: a62a56d0 ("ptp: ocp: Enable 4th timestamper / PPS generator") Link: https://github.com/ClangBuiltLinux/linux/issues/1457Suggested-by:Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by:
Nathan Chancellor <nathan@kernel.org> Acked-by:
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Yonghong Song authored
With clang building selftests/bpf, I hit a few warnings like below: .../bpf_iter.c:592:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable] __u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0; ^ .../bpf_iter.c:688:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable] __u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0; ^ .../tc_redirect.c:657:6: warning: variable 'target_fd' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!ASSERT_OK_PTR(nstoken, "setns " NS_FWD)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .../tc_redirect.c:743:6: note: uninitialized use occurs here if (target_fd >= 0) ^~~~~~~~~ Removing unused variables and initializing the previously-uninitialized variable to ensure these warnings are gone. Signed-off-by: -
Alexei Starovoitov authored
Andrii Nakryiko says: ==================== This patch set deprecates bpf_object_open_opts.attach_prog_fd (in libbpf 0.7+) by extending bpf_program__set_attach_target() to support some more flexible scenarios. Existing fexit_bpf2bpf selftest is updated accordingly to not use deprecated APIs. While at it, also deprecate no-op relaxed_core_relocs option (they are always "relaxed"). Last patch also const-ifies all high-level libbpf attach APIs, as there is no reason for them to assume bpf_program/bpf_map modifications. Patch #1 also removes one more unneeded use of find_sec_def(), relying on prog->sec_def that's set during bpf_object__open() operation, simplifying upcoming refactoring a little bit more. All these changes are preparatory patches before SEC() handling refactoring that will come next. ==================== Signed-off-by: -
Andrii Nakryiko authored
Attach APIs shouldn't need to modify bpf_program/bpf_map structs, so change all struct bpf_program and struct bpf_map pointers to const pointers. This is completely backwards compatible with no functional change. Signed-off-by:
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